Image scanning and processing system, method of scanning and processing an image and method of selecting one of a plurality of master files comprising data encoding a scanned image

ABSTRACT

An image scanning and processing system includes a scanner for generating a stream of data encoding a scanned image; a controller for controlling and processing data received from the scanner; and a file storage unit. In use, the stream of data is written to a master file saved in the file storage unit. The controller is configured to create a preview image with a lower data size than the scanned image from at least part of the data encoding the scanned image. The controller is configured to extract data encoding the preview image directly from the stream of data, and to write the extracted data to a thumbnail file. A method of scanning and processing an image, includes scanning an original and thereby generating a stream of data, encoding a scanned image, saving the scanned image in a master file, and creating a preview image with a lower data size than the scanned image from at least part of the data encoding the scanned image. Data encoding the preview image is extracted from the stream of data, and written to a thumbnail file.

[0001] The present application claims, under 35 U.S.C. § 119, thepriority benefit of European Patent Application No. 02078186.0 filedJun. 28, 2002, the entire contents of which are herein fullyincorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Filed of the Invention

[0003] The invention relates to an image scanning and processing system,comprising a scanner for generating a stream of data encoding a scannedimage; a controller for controlling and processing data received fromthe scanner; and a file storage wherein, in use, the stream of data iswritten to a master file saved in the file storage and the controller isconfigured to create a preview image with a lower data size than thescanned image from at least part of the data encoding the scanned image.

[0004] The invention also relates to a method of scanning and processingan image, comprising scanning an original and thereby generating astream of data, encoding the scanned image, saving the scanned image ina master file, and creating a preview image with a lower data size thanthe scanned image from at least part of the data encoding the scannedimage. The invention also relates to a method of selecting one of aplurality of master files comprising data encoding a scanned image.

[0005] 1. Discussion of the Related Art

[0006] When scanning a number of documents, for example for electronicarchiving purposes or to create copies, it is desirable that an operatorcan check the scanned image to determine whether the scan is of highenough quality. It may be desirable, for instance to check whether thescan resolution is high enough to show all the details in a criticalregion. It is thus desired that the operator be able to select certainregions in the scanned image, and be able to view them at the resolutionused to scan the original.

[0007] Examples of the above-mentioned method for scanning a document,and image scanning and processing system are known from European PatentApplication Publication No. 0 589 724A. This publication relates to anelectronic image processing system. In this system, an initialhigh-resolution image is held in a high capacity storing unit. Thesystem comprises a small capacity high speed storing unit and isarranged to transfer portions of the initial high-resolution image tothe small capacity high speed storing unit a portion at a time. Thesystem also comprises a viewing store for storing data representing animage to be displayed and a monitor for displaying the image. The systemis arranged to operate in a preview mode. In this preview mode, imagedata is down converted and written to a destination area for output tothe viewing store. The down-conversion of the data is performed by thecontrol processor.

[0008] In the prior art, if an operator wishes to select a section fromthe scanned image, a preview image of the entire scanned image wouldhave to be created first. This requires processing of all the datacomprised in the master file. From a display of the preview image, theuser would be able to select a section of the scanned image. This couldthen be retrieved from the master file for display. But, such a processis time consuming and strains the processing capacity of the controllerand its memory to the utmost. Additionally, if one wanted to check asecond area, the whole process would have to be repeated again,rendering the system to be rather inefficient.

SUMMRY OF THE INVENTION

[0009] It is an object of the invention to provide a system and methodsfor respectively allowing handling of scanned images with a large datasize in a speedy and efficient way.

[0010] It is another object of the invention to provide a system andmethod for scanning and processing images, which overcome problems andlimitations of the related art.

[0011] These and other objects are achieved with the system according toan embodiment of the invention, wherein the controller is configured toextract data encoding the preview image from the stream of data, and towrite the extracted data to a thumbnail file.

[0012] The method of scanning and processing an image according to anembodiment of the invention is provided wherein data encoding thepreview image is extracted from the stream of data, and written to athumbnail file. Thus, a small file is quickly made available. Eventhough it is a small file, it is representative of the entire area ofthe scanned image. Because it is created directly from the stream ofdata, it is available directly after, or even before the scanning isfinished. It can be used for a quick check of the scanning process, in agraphical user interface to select part(s) of the scanned image, orvisually to provide other information relating to the scanned image,without requiring processing of large amounts of data comprised in themaster file.

[0013] In one embodiment, at least part of the preview image isdisplayed to an operator as a survey view in a window on a display.Thus, it is possible to perform a quick first check for obvious scanningerrors, without loading any of the detailed information comprised in themaster file. Original skew, scanning of the original in the wrongdirection, or insertion of the original in a scanning array the wrongway up are all easily detectable.

[0014] In one embodiment, the part of the preview image is displayedbefore or during the saving to the thumbnail file. Thus, the first checkcan be performed at the earliest possible moment. This allows anoperator to break off the scanning process before the entire originalhas been scanned.

[0015] In a preferred embodiment, part of the scanned image representinga region of interest is displayed to an operator as a detailed view ofthe region of interest in a window on a display. Thus, it is possible toperform a more detailed check of the scanned image stored in the masterfile, without having to retrieve the entire master file and process allthe data contained therein. By checking a critical part of the scannedimage, for example a part containing very finely spaced lines or smalltext, an impression can be gained whether all details in the originalhave been captured by the scanning process.

[0016] An embodiment of the method according to the invention comprisesproviding a selection frame in the survey view, wherein an operatorselects the region of interest by sizing and positioning the selectionframe in the survey view. Thus, it is possible to select and view anydesired portion of the scanned image. Selection is extremely easy, sinceit can be done with reference to the scanned image, but it is notnecessary to load the entire scanned image stored in the master file.Thus, resources are spared and time is saved according to the presentinvention.

[0017] In one embodiment of the invention, the part of the scanned imagerepresenting the region of interest is converted to a different dataformat before being displayed. Thus, it is possible not only to assessthe quality of the scan, but also to see the effect that conversion ofthe data encoding the scanned image will have. This embodiment isparticularly appropriate when scanning to file for archiving purposes.It allows selection of a suitable file format for storing the scannedimage and/or for choosing scanning settings appropriate to the chosenfile format.

[0018] In a further development of this embodiment, the part of thescanned image representing the region of interest is compressed whenconverted to the different data format and is decompressed before beingdisplayed. Thus, it is possible for an operator to assess whether or notcompressing the scanned image before storage and decompressing afterretrieval will result in a poor rendering of the original image. It isthus possible to prevent loss of detail when storing to file in acompressed format for archiving purposes or for transmission of thescanned image. In each case, the entire scanned image need not beprocessed for the purpose of assessment by the operator. Rather, theoperator can select a region of interest containing elements allowinghim to form a judgement on the image quality. Only the data encodingthis region of interest need be processed.

[0019] In an embodiment of the invention, the scanned image is checkedfor artifacts, and information specifying detected artifacts is providedwith the preview image.

[0020] According to an aspect of the invention, a method of selectingone of a plurality of master files comprising data encoding a scannedimage, which can be created using a method of scanning and processingimages according to the present invention, is provided, wherein at leastpart of a thumbnail file comprising data encoding a preview imagecorresponding to the scanned image with a lower data size than thescanned image is sent to an archive manager, and wherein the archivemanager displays the parts as survey previews to the user.

[0021] Thus a particularly responsive and informative user interface isprovided for selecting archived images. Due to the survey previews, theuser knows which image is stored in each master file. Because thethumbnail is already present, it is not necessary to scale down eachmaster file in turn to build up the display.

[0022] These and other objects of the present application will becomemore readily apparent from the detailed description given hereinafter.However, it should be understood that the detailed description andspecific examples, while indicating preferred embodiments of theinvention, are given by way of illustration only, since various changesand modifications within the spirit and scope of the invention willbecome apparent to those skilled in the art from this detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The invention will now be explained in further detail withreference to the accompanying drawings.

[0024]FIG. 1 is a simplified component diagram depicting an embodimentof a scanning and processing system according to the invention.

[0025]FIG. 2 is a schematic illustration of an embodiment of the systemshown in FIG. 1.

[0026]FIG. 3 is a schematic cross-sectional diagram of an embodiment ofa scanning device for use in connection with the invention.

[0027]FIG. 4 is a schematic example of a screen view, provided duringexecution of an embodiment of a method of scanning and processing imagesaccording to the invention.

[0028]FIG. 5 is a flow diagram showing an embodiment of the method ofscanning and processing images according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029]FIG. 1 is an example of a block diagram of a system for scanningand processing images according to an embodiment of the presentinvention. Referring to FIG. 1, the scanning and processing systemaccording to the invention comprises a scanner 1 for scanning anoriginal, a printing device 33, a controller 10, a file storage unit ormeans 13, one or more terminals 36 coupled with a network 37, an inputunit or means 21, and a display unit or means 14, all operativelycoupled. Some of these elements may be omitted depending on theapplication. For instance, if the originals are scanned for copyingdocuments, then the printing device 33 is needed but the terminals 36may not be needed. If the originals are scanned for electronicarchiving, then the printing device 33 may not be needed and theterminals 36 may be needed.

[0030] The scanner 1 can be part of a copier or part of a stand-alonedevice. FIG. 2 shows an example of the scanner 1 of the latter type, asa scanning device 2. The scanning device 2 is a throughput scanner,meaning that it comprises a stationary scanning array, and a feedermechanism for moving an original past the scanning array. The inventioncan, however, also be implemented using a flatbed-scanning device, inwhich the scanning array is moved across the original, or any other typeof a scanning device.

[0031] A schematic cross-sectional view of the scanning device 2according to one embodiment of the present invention is shown in FIG. 3.As shown in FIGS. 2 and 3, the original is placed on an original table3, and pulled through the device 2 by a feeder mechanism comprising twopairs 4, 5 of transport rollers. The device 2 further comprises a lightsource 6 and a transparent plate 7 for guiding the original sheet. Thetransparent plate 7 provides an exposure area 8. Light from the lightsource 6 is projected along an optical path (shown as a dashed line)onto a CCD array 9. The CCD array 9 is an array of charge coupleddevices, but other types of light detecting devices may be used in lieuof the CCD array 9.

[0032] The invention can be used for scanning any type of image, on anytype of original, but is particularly useful for scanning wide formatoriginals comprising colour images with randomly distributed areascontaining small details. Engineering drawings are a typical example ofsuch originals. Although the maximum width of the original is determinedby the width of the scanning array 9, the length is not limited by thephysical dimensions of the scanning device 2.

[0033] The scanning device 2 is capable of scanning originals at severaldifferent resolutions and in several different colour modes. A 1-bitblack-and-white mode is possible, but a 24-bit full colour mode isequally possible. In this case, each sample point results in a 24-bitdata element. A DIN-A0 sized original, scanned in a 24-bit full colourmode at 600 dots per inch resolution, will result in the image on theoriginal being encoded in approximately 1.6 Gbytes of data.

[0034] The controller 10 in the scanning and processing system isprovided for controlling and processing the data received from thescanning array 9. The term “controller” in this context is used todenote a combination of hardware and software that performs specificfunctions in the scanning and processing system. This includescoordination of the various steps needed to scan and process an image,execution of a large number of these steps, and the directing of datastreams between the various other components of the scanning andprocessing system.

[0035] In the system of FIG. 2, the controller 10 substantiallycomprises a series of software modules on a workstation 11.Alternatively, the controller 10 or part of the controller 10, could becomprised in the scanning device 2. In this embodiment, the workstation11 is a computer with at least one processor, random access memory, ahard disk and graphics and network cards.

[0036] In operation, the original sheet is transported by the pairs 4,5of rollers along the transparent plate 7 and across the exposure area 8.The light source 6 illuminates the original sheet at the exposure area8. An image line of the original document at the image plane isprojected via the optical path on the CCD array 9. Electrical signalsgenerated in the elements of the CCD array 9 in correspondence with theline image in the exposure area 8 are read out in parallel and placed ina line buffer. The line buffer is read out for further processing.

[0037] In one embodiment, a method for scanning and processing imagesaccording to the invention is illustrated in FIG. 5, and isimplementable in the system shown in FIG. 1 or 2. In a first step S12,the data encoding the scanned image is passed in a stream from thescanner 1 to the controller 10, where it is processed. According to theinvention, the controller 10 creates a separate stream of data encodinga preview image with a lower data size from the stream of data comingfrom the scanner 1. In other words, the original image is scaled down.

[0038] There are a number of ways in which the original image can bescaled down. The invention can use any one of them. Pixel sub-samplingis a basic example of a scaling method. In the pixel sub-sampling, thebit map is resampled, e.g. for a scaling factor of 1:100, ninety-ninepixels over one are removed in both directions. This method has theadvantage of being fast. Other methods which may be used are, forexample, random pixel sub-sampling and black pixel conservation. Thesemethods have the advantage of reducing the data size with a less severeloss of information. Scaling down is carried out on the stream of datathat has been read out as it arrives at the controller 10, so as togenerate a preview image. The preview image is thus generated on thefly.

[0039] The extracted data encoding the preview image is then written toa thumbnail file stored on the storage means 13 connected to thecontroller 10. The storage means 13 can be any means to store data, andfor example, may comprise a solid state memory and/or a magnetic harddisk. In the implementation of the system in FIG. 1, the storage means13 can be a hard disk in the scanning device 2, in the workstation 11,or a replaceable storage medium.

[0040] On the other hand, the primary stream of data, which encodes thescanned image in a format with a higher data size, is written to amaster file on the storage means 13. Because the preview image encodedin the thumbnail file has a much smaller data size compared to theprimary stream of data stored in the master file, it can be retrievedquickly and transferred between devices quickly without requiringdatabuses or network connections with a high bandwidth.

[0041] In the system of FIG. 2, the display means 14 comprise a display15 in the scanning device 2 and a monitor 16 connected to theworkstation 11. An example of a screen view 17 displayable on thedisplay means 14 is shown in FIG. 4.

[0042] In FIG. 4, the screen view 17 comprises a first window 18 inwhich a survey view 19 is provided. The first window 18 is generatedfrom the preview image. The survey view 19 can comprise all or part ofthe preview image. A system in which the operator can specify an area ofthe image to be used to provide the survey view 19 falls within thescope of the invention.

[0043] Completion of the generation of the thumbnail file marks thestart of operation of the present system. In one embodiment, the surveyview 19 is displayed after scanning the original sheet(s), once thethumbnail file has been completely stored.

[0044] In an advantageous alternative embodiment, the survey view 19 isbuilt up on the fly, by directing the data stream encoding the previewimage to the means 14 of display as well as to the thumbnail file. Thus,the operator can break off the scanning process if an error is detectedhalfway through.

[0045] In a preferred embodiment the scanning process comprises animage-processing step on the primary stream of data before the creationof the preview image. The image processing is preferably carried out onthe stream of data read from the line buffer, i.e. on the fly, todecrease the burden on the controller 10. As an example, automaticbackground compensation can be carried out at this stage. By carryingout this algorithm on the fly, account can be taken of gradualvariations in the background intensity level across a very large image.Alternative image processing algorithms that can be carried out on theprimary data stream from which the master file and thumbnail file arecreated, include gamut mapping, deskewing and despeckling.

[0046] The survey view 19 is provided for two purposes. Firstly, itallows an operator to gain a quick first impression of the quality ofthe scanned image. Secondly, it is used to provide a graphical means ofselecting an area of the scanned image encoded in the master file, inorder to carry out a check of the quality of this scanned image, andalso in order to check the legends for identification.

[0047] For the second purpose, the first window 18 comprises a selectionframe 20 laid over the survey view 19. The input means 21 are providedwith the system with which an operator can size and position theselection frame 20 within the first window 18 to select a Region ofInterest (ROI). It will be understood that the input means 21 cancomprise buttons on a control panel 22 of the scanning device 2, a mouse23 or keyboard 24 connected to the workstation 11, a touch-sensitivescreen mechanism, a voice-activated mechanism, etc. This will depend onthe chosen implementation of the means of display 14, and is notessential to the invention.

[0048] The screen view 17 of FIG. 4 comprises a second window 25including a detailed view 26 of the scanned image. The detailed view 26corresponds to the ROI, but it is generated from the master file. Thedetailed view 26 thus allows a more thorough check of the quality of thescanned image encoded in the master file. By resizing and/or positioningthe selection frame 20 within the first window 18 or by operating scrollbars (not shown) of the second window 25, the operator can select aparticular area of the image that enables the most effective check ofthe quality. For example, this can be the annotation or a hatched areain a scanned engineering drawing. In one example, the default positionof the selection frame 20 is at the legends, but can be at any otherpredesignated item or location.

[0049] Of course, the invention is not dependent on a particulararrangement of the detailed view 26 and the survey view 19 as shown inFIG. 4. For example, other implementations of the invention arepossible, wherein the detailed view 26 and the survey view 19 arepresented in one window, for example, wherein the part of the surveyview 19 defined by the selection frame 20 is replaced by the detailedview 26 of the ROI. Alternatively, the first and second windows 18,25can be sequentially displayed one over the other or one at a time.

[0050] In a further developed embodiment of the invention, the scannedimage is checked for artifacts in step S12 and information specifyingthe detected artifacts is provided with the preview image. Theimage-processing step is used to check for artifacts, so the check ofthe image is also carried out by analyzing the data in the primary datastream on the fly.

[0051] An artifact in this context is a part of the encoded image thatpossesses certain predefined characteristics. Usually, this will be adeparture from the normal, expected characteristics, indicative of aproblem in the scanning process. For example, when certain lines areconsistently black in a scan generated with the CCD array 9, this couldbe indicative of a contamination of the scanner 1. A uniformly gray areain the scanned image might be indicative of an area of considerabledetail that is not adequately captured due to a scanning resolution thatis too coarse.

[0052] An indication of the location and, optionally, the type ofdetected artifact is provided with the data destined for the thumbnailfile. This indication is used to display automatically the affected areain the survey view 19 and/or the detailed view 26. As an enhancement,the affected area can be highlighted, for example in a different colour,in the survey view 19 and/or the detailed view 26, to draw the attentionof the user. The type of artifact can be made known to the user, forexample by using a different type of highlighting, an annotation, orsome other means. Especially if the data encoding the preview image andthe detected artifact is directly used to create the survey view 19, theuser thus has at his disposal a means for quickly and automaticallydetecting problems in the scanning process. Scanning of the original canthus be cancelled at an early stage, if the user deems it necessary. Ifthe artifact is not problematic, scanning can continue as normal.

[0053] After the document has been scanned, in step S27 of the flowdiagram of FIG. 5, a scale ratio is used to translate coordinates(X_(T), Y_(T)), representing the center point of the selection frame 20in the preview image in the thumbnail file, into coordinates (X_(m),y_(m)) corresponding to the same position in the scanned image in themaster file, so as to determine the location (coordinates) of the ROI.In a next step S28, the data encoding the ROI is extracted from themaster file. The system then uses the extracted data to build up adetailed view 26.

[0054] In the diagram of FIG. 5, it can be seen that the systeminitially executes steps S27 and S28 immediately after step S12. In thisinitial phase, the system uses a default ROI or an ROI that has beenspecified in advance by the user.

[0055] A preferred embodiment of the system according to the inventionallows the master file to be converted and stored in a different dataformat. Examples of such data formats that can be used are the GraphicsInterchange Format, Tagged Image File Format, Portable Document Formatand Computer Aided Acquisition and Logistics Support format.

[0056] Preferably, the controller 10 is capable of generating acompressed version of the master file. Some of the image formats justmentioned make use of a standard image compression algorithm, in whichcase the selection of a file format automatically entails the selectionsof a specific compression algorithm. Other file formats allow severaltypes of compression to be used. Varieties of the invention wherein thecompression algorithm and file format can be independently selected arepossible. It is equally possible that the present system provides theuser a choice of file formats and then automatically selects a defaultcompression algorithm associated with the selected file format.

[0057] In the embodiment for which FIG. 5 provides a flow diagram, theoperator is able to choose between several types of compression, or tochoose no compression at all. The present system enables the operator tojudge the effects of different types of compression before committinghimself to one of them.

[0058] There are two categories of compression, lossy and lossless. Alossy compression algorithm results in a compressed image that comprisesless information than the original. Lossy compression algorithms, forexample, use a quantization step that rounds off coefficients encodingthe image. A lossless compression algorithm does not result in loss ofinformation, but does pare down the amount of data, typically byencoding the data in a more efficient way.

[0059] Whenever a lossy type of compression has been selected in stepS25, the detailed view 26 is generated by first compressing the dataencoding the ROI and then decompressing the compressed data in step S29.The present system then executes step S30 in which the detailed view 26is displayed in the second window 25 or in some appropriate manner asdiscussed above. If a lossy type of compression is not selected in stepS25, then step S30 is performed. Thus, the operator can judge whetherthe loss of data is acceptable, or whether a different file formatshould be chosen.

[0060] Because only the ROI is compressed and then decompressed, theoperator is able to reach a conclusion fairly quickly. It is notnecessary to compress the entire master file, thus saving time andprocessing capacity. The master file is only compressed and saved in itsentirety in steps S31 and S32, when the operator has signalled hissatisfaction by issuing the appropriate command, e.g., via the inputmeans 21.

[0061] Preferably, the present system ensures that the part of thescanned image representing the region of interest is chosen to be largerthan a size leading to compression artifacts. This feature is onlymeaningful in combination with certain types of compression algorithms.The algorithms decompose the image into a number of spatial frequencycomponents. Distortion of the image occurs, when the number of pixels inthe ROI is too small. In this case, the higher frequency componentscannot be accurately determined. Reconstruction of the image, duringdecompression, will result in an image with artifacts, especially in thesections of the image adjacent to the boundaries. This can be preventedby ensuring that the ROI is large enough compared to the sample size ofthe compression algorithm.

[0062] Various implementations of the means of ensuring this areconceivable within the scope of the invention. It is also possible toprevent a user from resizing the selection frame 20 below certaindimensions. Another variant would be to increase the size of theselected ROI to the specified minimum dimensions automatically.

[0063]FIG. 5 illustrates the fact that the user can try out severaldifferent file formats before committing himself to one of them. If thedetailed view 26 generated on the display means 14 in step S30 is notsatisfactory, the file format can be changed in step S38 and then stepsS25, S29 and S30 are repeated.

[0064] On the other hand, if the user desires to check several parts ofthe image, the selection frame 20 can be resized or moved in step S39,in which case the system returns to step S27 to generate a new detailedview 26 of the ROI that has now been selected. An automatic return tostep S27 implies an embodiment of the invention wherein the detailedview 26 is automatically updated upon resizing or repositioning of theselection frame 20. In variants of the present system, the access timeof the file storage means 13 or the bandwidth of connections between thecontroller 10 and file storage means 13 could be limited compared to theamount of data encoding the image in the master file. In that case, atrigger, e.g. a user command, could be specified to start the build-upof the detailed view 26. This would make the system faster.

[0065] Finally, the user has the option to indicate his satisfaction byissuing the command to save the master file, e.g., using the input means21 (step S40). If the master file is not to be saved, then the processreturns to step S38. But, when the user has entered the appropriatecommand, the master file is saved. Whenever a certain type of imagecompression has been specified (step S41), either explicitly orimplicitly through the selection of a file format that involves imagecompression, the master file will be compressed in step S31, beforebeing saved in the specified file format in step S32.

[0066] The invention can be used both to scan documents to create anelectronic archive, or for copying documents. The schematic diagram ofFIG. 1 shows a printing device 33 connected to the controller 10. InFIG. 2, this is implemented in the shape of a printer 34 with a documentfolder and collator 35 attached. The arrangement of FIG. 2 is especiallyuseful for generating copies of wide-format documents.

[0067] The printing device 33 can use any number of printing techniques.It can be a thermal inkjet printer, a pen plotter, or a press systembased on organic photoconductor technology, for instance.

[0068] To illustrate the use of the invention in connection with anelectronic archive, the system of FIG. 1 comprises several terminals 36.The terminals 36 can gain access to the file storage means 13 through anetwork 37. In this case, access involves the controller 10, but it willbe understood that where the file storage means 13 comprise a separateserver, this server would be directly connected to the network 37.

[0069] For ease of access, the thumbnail file is preferably saved withthe master file. An archive manager 38 is used to display at least partof the image encoded in the thumbnail file to the user of a terminal 36.The archive manager 38 can be part of the controller 10 as shown in FIG.1, but can be part of any other element or be an independent element.Indeed, a number of survey previews of stored images can be provided ina menu. This enables the user to recognize the image. Because there isless data in the thumbnail file, the archive manager can build up theselection menu with the survey previews quickly, and more previews canbe used. Because the thumbnail files that have originally been createdduring the scanning process are used, there is no need to wait for thesystem to recreate the survey previews from the stored master files.Thus, the user can browse through the repository of images in the storedmaster files.

[0070] The steps of the present method according to the presentinvention are implementable using existing computer programminglanguage. Such computer program(s) may be stored in memories such asRAM, ROM, PROM, etc. associated with computers. Alternatively, suchcomputer program(s) may be stored in a different storage medium such asa magnetic disc, optical disc, magneto-optical disc, etc. Such computerprogram(s) may also take the form of a signal propagating across theInternet, extranet, intranet or other network and arriving at thedestination device for storage and implementation. The computer programsare readable using a known computer or computer-based device.

[0071] It will be obvious to those skilled in the art that the inventionis not limited to the described embodiments, but can be varied withinthe scope of the claims. In particular, the description is not intendedto limit the invention to certain categories of image compression, beingmerely intended to be applicable to several of the most common types ofimage compression and file formats.

1. An image scanning and processing system, comprising a scanner forgenerating a stream of data encoding a scanned image; a controller forcontrolling and processing data received from the scanner; and filestorage means, wherein, in use, the stream of data is written to amaster file saved in the file storage means, and the controller isconfigured to create a preview image with a lower data size than thescanned image from at least part of the data encoding the scanned image,wherein the controller is further configured to extract data encodingthe preview image from the stream of data, and to write the extracteddata to a thumbnail file.
 2. The system according to claim 1, furthercomprising: a display unit for displaying at least a portion of thepreview image and for displaying in more detail a section of thedisplayed preview image according to a user's selection of the section.3. The system according to claim 2, wherein the display unit provides aselection frame with which the user makes the user's selection of thesection, the selection frame being resizable and movable.
 4. The systemaccording to claim 2, wherein the selected selection of the previewimage is converted to a different data format before being displayed. 5.The system according to claim 1, wherein the scanner or the controllerchecks the scanned image for artifacts, and stores informationspecifying the detected artifacts with the preview image in the filestorage means.
 6. A method of scanning and processing an image,comprising: scanning an original and thereby generating a stream ofdata; encoding a scanned image; saving the scanned image in a masterfile; and creating a preview image with a lower data size than thescanned image from at least part of the data encoding the scanned image,wherein data encoding the preview image is extracted from the stream ofdata, and written to a thumbnail file.
 7. The method according to claim6, wherein the preview image is a lower resolution rendition of at leastpart of the scanned image.
 8. The method according to claim 6, whereinat least part of the preview image is displayed to an operator as asurvey view in a window on a display.
 9. The method according to claim8, wherein the part of the preview image is displayed before or duringthe saving to the thumbnail file.
 10. The method according to claim 6,wherein part of the scanned image representing a region of interest isdisplayed to an operator as a detailed view of the region of interest ina window on a display.
 11. The method according to claim 8, furthercomprising: providing a selection frame in the survey view, wherein anoperator selects a region of interest by sizing and positioning theselection frame in the survey view.
 12. The method according to claim10, wherein the part of the scanned image representing the region ofinterest is converted to a different data format before being displayed.13. The method according to claim 12, wherein the part of the scannedimage representing the region of interest is compressed when convertedto the different data format and decompressed before being displayed.14. The method according to claim 13, wherein the part of the scannedimage representing the region of interest is chosen to be larger than asize leading to compression artifacts.
 15. The method according to claim6, further comprising: image-processing the stream of data beforecreation of the preview image.
 16. The method according to claim 6,wherein the scanned image is checked for artifacts, and whereininformation specifying the detected artifacts is provided with thepreview image.
 17. A method for selecting one of a plurality of masterfiles comprising data encoding at least one scanned image, wherein themaster file is created by scanning an original and thereby generating astream of data, encoding a scanned image, and saving the scanned imagein a master file, the method comprising: providing at least part of athumbnail file associated with one of the master files to an archivemanager, said part of the thumbnail file including data encoding apreview image corresponding to the scanned image with a lower data sizethan the scanned image, whereby the archive manager can display theparts as survey previews to the user for selection.